Am 16.08.2018 um 15:05 schrieb Emily Deng:
> To avoid the tlb flush not interrupted by world switch, use kiq and one
> command to do tlb invalidate.
>
> Signed-off-by: Emily Deng <Emily.Deng at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu.h | 4 +++
> drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c | 3 --
> drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c | 60 ++++++++++++++++++++++++++++++++
> 3 files changed, 64 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 6265b88..19ef7711 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -212,6 +212,10 @@ enum amdgpu_kiq_irq {
> AMDGPU_CP_KIQ_IRQ_LAST
> };
>
> +#define MAX_KIQ_REG_WAIT 5000 /* in usecs, 5ms */
> +#define MAX_KIQ_REG_BAILOUT_INTERVAL 5 /* in msecs, 5ms */
> +#define MAX_KIQ_REG_TRY 20
> +
> int amdgpu_device_ip_set_clockgating_state(void *dev,
> enum amd_ip_block_type block_type,
> enum amd_clockgating_state state);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
> index 21adb1b6..3885636 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
> @@ -22,9 +22,6 @@
> */
>
> #include "amdgpu.h"
> -#define MAX_KIQ_REG_WAIT 5000 /* in usecs, 5ms */
> -#define MAX_KIQ_REG_BAILOUT_INTERVAL 5 /* in msecs, 5ms */
> -#define MAX_KIQ_REG_TRY 20
>
> uint64_t amdgpu_csa_vaddr(struct amdgpu_device *adev)
> {
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> index ed467de..6c164bd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> @@ -311,6 +311,58 @@ static uint32_t gmc_v9_0_get_invalidate_req(unsigned int vmid)
> return req;
> }
>
> +signed long amdgpu_kiq_reg_write_reg_wait(struct amdgpu_device *adev,
> + uint32_t reg0, uint32_t reg1,
> + uint32_t ref, uint32_t mask)
> +{
> + signed long r, cnt = 0;
> + unsigned long flags;
> + uint32_t seq;
> + struct amdgpu_kiq *kiq = &adev->gfx.kiq;
> + struct amdgpu_ring *ring = &kiq->ring;
> +
> + if (!ring->ready)
> + return -EINVAL;
> +
> + spin_lock_irqsave(&kiq->ring_lock, flags);
> +
> + amdgpu_ring_alloc(ring, 32);
> + amdgpu_ring_emit_reg_write_reg_wait(ring, reg0, reg1,
> + ref, mask);
> + amdgpu_fence_emit_polling(ring, &seq);
> + amdgpu_ring_commit(ring);
> + spin_unlock_irqrestore(&kiq->ring_lock, flags);
> +
> + r = amdgpu_fence_wait_polling(ring, seq, MAX_KIQ_REG_WAIT);
> +
> + /* don't wait anymore for gpu reset case because this way may
> + * block gpu_recover() routine forever, e.g. this virt_kiq_rreg
> + * is triggered in TTM and ttm_bo_lock_delayed_workqueue() will
> + * never return if we keep waiting in virt_kiq_rreg, which cause
> + * gpu_recover() hang there.
> + *
> + * also don't wait anymore for IRQ context
> + * */
> + if (r < 1 && (adev->in_gpu_reset || in_interrupt()))
> + goto failed_kiq;
> +
> + might_sleep();
> +
> + while (r < 1 && cnt++ < MAX_KIQ_REG_TRY) {
> + msleep(MAX_KIQ_REG_BAILOUT_INTERVAL);
> + r = amdgpu_fence_wait_polling(ring, seq, MAX_KIQ_REG_WAIT);
> + }
> +
> + if (cnt > MAX_KIQ_REG_TRY)
> + goto failed_kiq;
> +
> + return 0;
> +
> +failed_kiq:
> + pr_err("failed to invalidate tlb with kiq\n");
> + return r;
> +}
> +
> /*
> * GART
> * VMID 0 is the physical GPU addresses as used by the kernel.
> @@ -332,6 +384,7 @@ static void gmc_v9_0_flush_gpu_tlb(struct amdgpu_device *adev,
> /* Use register 17 for GART */
> const unsigned eng = 17;
> unsigned i, j;
> + int r;
>
> spin_lock(&adev->gmc.invalidate_lock);
>
> @@ -339,6 +392,13 @@ static void gmc_v9_0_flush_gpu_tlb(struct amdgpu_device *adev,
> struct amdgpu_vmhub *hub = &adev->vmhub[i];
> u32 tmp = gmc_v9_0_get_invalidate_req(vmid);
>
> + spin_unlock(&adev->gmc.invalidate_lock);
Well just remove the lock altogether. Taking it and dropping it again
immediately doesn't do anything useful.
> + r = amdgpu_kiq_reg_write_reg_wait(adev, hub->vm_inv_eng0_req + eng,
> + hub->vm_inv_eng0_ack + eng, tmp, 1 << vmid);
> + spin_lock(&adev->gmc.invalidate_lock);
> + if (!r)
> + continue;
> +
> WREG32_NO_KIQ(hub->vm_inv_eng0_req + eng, tmp);
>
> /* Busy wait for ACK.*/
Since you now use the KIQ to wait for the TLB flush I think we can now
remove the MMIO implementation.
Regards,
Christian.
